Changes added due the removal of the path field from the tags table

Changes added due the removal of the path field from the tags table
This changes will affect all the componnet who is using `JTableNested` methods. Todo: Make sure that you maintain all exisitng joomla componnet. We definitly need inputs on this from community. You may write here https://groups.google.com/forum/#!forum/joomla-dev-cms if you need any further help. :)